Many anchor bolts which utilize an expansion feature are effectively useful only with hollow walls, because the expanding feature is designed to undergo a compound movement during deployment, i.e. to pivot outwards and axially toward the bolt head.
Other expansion-type anchor bolts meant for use within the matrix of a solid material such as concrete, rock, coal and the like rely for anchoring on a jam fit produced by radial expansion of the anchor bolt, accompanied by corresponding axial shortening after the anchor bolt has been inserted in a socket in the matrix.
In other instances expansion requires a deformation of a tubular portion of the bolt and/or of a bolt jacket portion. This effectively rules out the use as bolt-fabricating material of strong, hard metals which happen to be too brittle to be successfully deformed in the expansion process.
For constructing anchor bolts of strong, hard metals for use in matrices of solid material such as rock, concrete and coal, a classical solution has been to bore or otherwise form a considerably oversize socket, to insert the anchor bolt in the oversize socket with its anchors already fully and often fixedly deployed, and then to cement-fill excess volume of space around the anchor bolt in the socket, e.g. using metal-filled epoxy resin, an epoxy-laced mortar, or the like.